5 * Copyright (c) 2004 Freescale Semiconductor, Inc.
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License as published by the
9 * Free Software Foundation; either version 2 of the License, or (at your
10 * option) any later version.
14 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
16 #include <linux/kernel.h>
17 #include <linux/string.h>
18 #include <linux/errno.h>
19 #include <linux/unistd.h>
20 #include <linux/slab.h>
21 #include <linux/interrupt.h>
22 #include <linux/init.h>
23 #include <linux/delay.h>
24 #include <linux/device.h>
25 #include <linux/gpio.h>
26 #include <linux/gpio/consumer.h>
27 #include <linux/of_device.h>
28 #include <linux/of_mdio.h>
29 #include <linux/of_gpio.h>
30 #include <linux/netdevice.h>
31 #include <linux/etherdevice.h>
32 #include <linux/skbuff.h>
33 #include <linux/spinlock.h>
35 #include <linux/module.h>
36 #include <linux/mii.h>
37 #include <linux/ethtool.h>
38 #include <linux/phy.h>
40 #include <linux/uaccess.h>
41 #include <linux/gpio/consumer.h>
45 #define CREATE_TRACE_POINTS
46 #include <trace/events/mdio.h>
48 #include "mdio-boardinfo.h"
50 static int mdiobus_register_gpiod(struct mdio_device *mdiodev)
52 struct gpio_desc *gpiod = NULL;
54 /* Deassert the optional reset signal */
55 if (mdiodev->dev.of_node)
56 gpiod = fwnode_get_named_gpiod(&mdiodev->dev.of_node->fwnode,
57 "reset-gpios", 0, GPIOD_OUT_LOW,
60 if (PTR_ERR(gpiod) == -ENOENT || PTR_ERR(gpiod) == -ENOSYS)
63 return PTR_ERR(gpiod);
66 mdiodev->reset = gpiod;
68 /* Assert the reset signal again */
69 mdio_device_reset(mdiodev, 1);
74 int mdiobus_register_device(struct mdio_device *mdiodev)
78 if (mdiodev->bus->mdio_map[mdiodev->addr])
81 if (mdiodev->flags & MDIO_DEVICE_FLAG_PHY) {
82 err = mdiobus_register_gpiod(mdiodev);
87 mdiodev->bus->mdio_map[mdiodev->addr] = mdiodev;
91 EXPORT_SYMBOL(mdiobus_register_device);
93 int mdiobus_unregister_device(struct mdio_device *mdiodev)
95 if (mdiodev->bus->mdio_map[mdiodev->addr] != mdiodev)
98 mdiodev->bus->mdio_map[mdiodev->addr] = NULL;
102 EXPORT_SYMBOL(mdiobus_unregister_device);
104 struct phy_device *mdiobus_get_phy(struct mii_bus *bus, int addr)
106 struct mdio_device *mdiodev;
108 if (addr < 0 || addr >= ARRAY_SIZE(bus->mdio_map))
111 mdiodev = bus->mdio_map[addr];
116 if (!(mdiodev->flags & MDIO_DEVICE_FLAG_PHY))
119 return container_of(mdiodev, struct phy_device, mdio);
121 EXPORT_SYMBOL(mdiobus_get_phy);
123 bool mdiobus_is_registered_device(struct mii_bus *bus, int addr)
125 return bus->mdio_map[addr];
127 EXPORT_SYMBOL(mdiobus_is_registered_device);
130 * mdiobus_alloc_size - allocate a mii_bus structure
131 * @size: extra amount of memory to allocate for private storage.
132 * If non-zero, then bus->priv is points to that memory.
134 * Description: called by a bus driver to allocate an mii_bus
135 * structure to fill in.
137 struct mii_bus *mdiobus_alloc_size(size_t size)
140 size_t aligned_size = ALIGN(sizeof(*bus), NETDEV_ALIGN);
144 /* If we alloc extra space, it should be aligned */
146 alloc_size = aligned_size + size;
148 alloc_size = sizeof(*bus);
150 bus = kzalloc(alloc_size, GFP_KERNEL);
154 bus->state = MDIOBUS_ALLOCATED;
156 bus->priv = (void *)bus + aligned_size;
158 /* Initialise the interrupts to polling */
159 for (i = 0; i < PHY_MAX_ADDR; i++)
160 bus->irq[i] = PHY_POLL;
164 EXPORT_SYMBOL(mdiobus_alloc_size);
166 static void _devm_mdiobus_free(struct device *dev, void *res)
168 mdiobus_free(*(struct mii_bus **)res);
171 static int devm_mdiobus_match(struct device *dev, void *res, void *data)
173 struct mii_bus **r = res;
175 if (WARN_ON(!r || !*r))
182 * devm_mdiobus_alloc_size - Resource-managed mdiobus_alloc_size()
183 * @dev: Device to allocate mii_bus for
184 * @sizeof_priv: Space to allocate for private structure.
186 * Managed mdiobus_alloc_size. mii_bus allocated with this function is
187 * automatically freed on driver detach.
189 * If an mii_bus allocated with this function needs to be freed separately,
190 * devm_mdiobus_free() must be used.
193 * Pointer to allocated mii_bus on success, NULL on failure.
195 struct mii_bus *devm_mdiobus_alloc_size(struct device *dev, int sizeof_priv)
197 struct mii_bus **ptr, *bus;
199 ptr = devres_alloc(_devm_mdiobus_free, sizeof(*ptr), GFP_KERNEL);
203 /* use raw alloc_dr for kmalloc caller tracing */
204 bus = mdiobus_alloc_size(sizeof_priv);
207 devres_add(dev, ptr);
214 EXPORT_SYMBOL_GPL(devm_mdiobus_alloc_size);
217 * devm_mdiobus_free - Resource-managed mdiobus_free()
218 * @dev: Device this mii_bus belongs to
219 * @bus: the mii_bus associated with the device
221 * Free mii_bus allocated with devm_mdiobus_alloc_size().
223 void devm_mdiobus_free(struct device *dev, struct mii_bus *bus)
227 rc = devres_release(dev, _devm_mdiobus_free,
228 devm_mdiobus_match, bus);
231 EXPORT_SYMBOL_GPL(devm_mdiobus_free);
234 * mdiobus_release - mii_bus device release callback
235 * @d: the target struct device that contains the mii_bus
237 * Description: called when the last reference to an mii_bus is
238 * dropped, to free the underlying memory.
240 static void mdiobus_release(struct device *d)
242 struct mii_bus *bus = to_mii_bus(d);
243 BUG_ON(bus->state != MDIOBUS_RELEASED &&
244 /* for compatibility with error handling in drivers */
245 bus->state != MDIOBUS_ALLOCATED);
249 static struct class mdio_bus_class = {
251 .dev_release = mdiobus_release,
254 #if IS_ENABLED(CONFIG_OF_MDIO)
255 /* Helper function for of_mdio_find_bus */
256 static int of_mdio_bus_match(struct device *dev, const void *mdio_bus_np)
258 return dev->of_node == mdio_bus_np;
261 * of_mdio_find_bus - Given an mii_bus node, find the mii_bus.
262 * @mdio_bus_np: Pointer to the mii_bus.
264 * Returns a reference to the mii_bus, or NULL if none found. The
265 * embedded struct device will have its reference count incremented,
266 * and this must be put once the bus is finished with.
268 * Because the association of a device_node and mii_bus is made via
269 * of_mdiobus_register(), the mii_bus cannot be found before it is
270 * registered with of_mdiobus_register().
273 struct mii_bus *of_mdio_find_bus(struct device_node *mdio_bus_np)
280 d = class_find_device(&mdio_bus_class, NULL, mdio_bus_np,
283 return d ? to_mii_bus(d) : NULL;
285 EXPORT_SYMBOL(of_mdio_find_bus);
287 /* Walk the list of subnodes of a mdio bus and look for a node that
288 * matches the mdio device's address with its 'reg' property. If
289 * found, set the of_node pointer for the mdio device. This allows
290 * auto-probed phy devices to be supplied with information passed in
293 static void of_mdiobus_link_mdiodev(struct mii_bus *bus,
294 struct mdio_device *mdiodev)
296 struct device *dev = &mdiodev->dev;
297 struct device_node *child;
299 if (dev->of_node || !bus->dev.of_node)
302 for_each_available_child_of_node(bus->dev.of_node, child) {
305 addr = of_mdio_parse_addr(dev, child);
309 if (addr == mdiodev->addr) {
310 dev->of_node = child;
311 dev->fwnode = of_fwnode_handle(child);
316 #else /* !IS_ENABLED(CONFIG_OF_MDIO) */
317 static inline void of_mdiobus_link_mdiodev(struct mii_bus *mdio,
318 struct mdio_device *mdiodev)
324 * mdiobus_create_device_from_board_info - create a full MDIO device given
325 * a mdio_board_info structure
326 * @bus: MDIO bus to create the devices on
327 * @bi: mdio_board_info structure describing the devices
329 * Returns 0 on success or < 0 on error.
331 static int mdiobus_create_device(struct mii_bus *bus,
332 struct mdio_board_info *bi)
334 struct mdio_device *mdiodev;
337 mdiodev = mdio_device_create(bus, bi->mdio_addr);
341 strncpy(mdiodev->modalias, bi->modalias,
342 sizeof(mdiodev->modalias));
343 mdiodev->bus_match = mdio_device_bus_match;
344 mdiodev->dev.platform_data = (void *)bi->platform_data;
346 ret = mdio_device_register(mdiodev);
348 mdio_device_free(mdiodev);
354 * __mdiobus_register - bring up all the PHYs on a given bus and attach them to bus
355 * @bus: target mii_bus
356 * @owner: module containing bus accessor functions
358 * Description: Called by a bus driver to bring up all the PHYs
359 * on a given bus, and attach them to the bus. Drivers should use
360 * mdiobus_register() rather than __mdiobus_register() unless they
361 * need to pass a specific owner module. MDIO devices which are not
362 * PHYs will not be brought up by this function. They are expected to
363 * to be explicitly listed in DT and instantiated by of_mdiobus_register().
365 * Returns 0 on success or < 0 on error.
367 int __mdiobus_register(struct mii_bus *bus, struct module *owner)
369 struct mdio_device *mdiodev;
371 struct gpio_desc *gpiod;
373 if (NULL == bus || NULL == bus->name ||
374 NULL == bus->read || NULL == bus->write)
377 BUG_ON(bus->state != MDIOBUS_ALLOCATED &&
378 bus->state != MDIOBUS_UNREGISTERED);
381 bus->dev.parent = bus->parent;
382 bus->dev.class = &mdio_bus_class;
383 bus->dev.groups = NULL;
384 dev_set_name(&bus->dev, "%s", bus->id);
386 /* We need to set state to MDIOBUS_UNREGISTERED to correctly release
387 * the device in mdiobus_free()
389 * State will be updated later in this function in case of success
391 bus->state = MDIOBUS_UNREGISTERED;
393 err = device_register(&bus->dev);
395 pr_err("mii_bus %s failed to register\n", bus->id);
399 mutex_init(&bus->mdio_lock);
401 /* de-assert bus level PHY GPIO reset */
402 gpiod = devm_gpiod_get_optional(&bus->dev, "reset", GPIOD_OUT_LOW);
404 dev_err(&bus->dev, "mii_bus %s couldn't get reset GPIO\n",
406 device_del(&bus->dev);
407 return PTR_ERR(gpiod);
409 bus->reset_gpiod = gpiod;
411 gpiod_set_value_cansleep(gpiod, 1);
412 udelay(bus->reset_delay_us);
413 gpiod_set_value_cansleep(gpiod, 0);
419 for (i = 0; i < PHY_MAX_ADDR; i++) {
420 if ((bus->phy_mask & BIT(i)) == 0) {
421 struct phy_device *phydev;
423 phydev = mdiobus_scan(bus, i);
424 if (IS_ERR(phydev) && (PTR_ERR(phydev) != -ENODEV)) {
425 err = PTR_ERR(phydev);
431 mdiobus_setup_mdiodev_from_board_info(bus, mdiobus_create_device);
433 bus->state = MDIOBUS_REGISTERED;
434 dev_dbg(&bus->dev, "probed\n");
439 mdiodev = bus->mdio_map[i];
443 mdiodev->device_remove(mdiodev);
444 mdiodev->device_free(mdiodev);
447 /* Put PHYs in RESET to save power */
448 if (bus->reset_gpiod)
449 gpiod_set_value_cansleep(bus->reset_gpiod, 1);
451 device_del(&bus->dev);
454 EXPORT_SYMBOL(__mdiobus_register);
456 void mdiobus_unregister(struct mii_bus *bus)
458 struct mdio_device *mdiodev;
461 if (WARN_ON_ONCE(bus->state != MDIOBUS_REGISTERED))
463 bus->state = MDIOBUS_UNREGISTERED;
465 for (i = 0; i < PHY_MAX_ADDR; i++) {
466 mdiodev = bus->mdio_map[i];
471 gpiod_put(mdiodev->reset);
473 mdiodev->device_remove(mdiodev);
474 mdiodev->device_free(mdiodev);
477 /* Put PHYs in RESET to save power */
478 if (bus->reset_gpiod)
479 gpiod_set_value_cansleep(bus->reset_gpiod, 1);
481 device_del(&bus->dev);
483 EXPORT_SYMBOL(mdiobus_unregister);
486 * mdiobus_free - free a struct mii_bus
487 * @bus: mii_bus to free
489 * This function releases the reference to the underlying device
490 * object in the mii_bus. If this is the last reference, the mii_bus
493 void mdiobus_free(struct mii_bus *bus)
495 /* For compatibility with error handling in drivers. */
496 if (bus->state == MDIOBUS_ALLOCATED) {
501 BUG_ON(bus->state != MDIOBUS_UNREGISTERED);
502 bus->state = MDIOBUS_RELEASED;
504 put_device(&bus->dev);
506 EXPORT_SYMBOL(mdiobus_free);
509 * mdiobus_scan - scan a bus for MDIO devices.
510 * @bus: mii_bus to scan
511 * @addr: address on bus to scan
513 * This function scans the MDIO bus, looking for devices which can be
514 * identified using a vendor/product ID in registers 2 and 3. Not all
515 * MDIO devices have such registers, but PHY devices typically
516 * do. Hence this function assumes anything found is a PHY, or can be
517 * treated as a PHY. Other MDIO devices, such as switches, will
518 * probably not be found during the scan.
520 struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr)
522 struct phy_device *phydev;
525 phydev = get_phy_device(bus, addr, false);
530 * For DT, see if the auto-probed phy has a correspoding child
531 * in the bus node, and set the of_node pointer in this case.
533 of_mdiobus_link_mdiodev(bus, &phydev->mdio);
535 err = phy_device_register(phydev);
537 phy_device_free(phydev);
538 return ERR_PTR(-ENODEV);
543 EXPORT_SYMBOL(mdiobus_scan);
546 * __mdiobus_read - Unlocked version of the mdiobus_read function
547 * @bus: the mii_bus struct
548 * @addr: the phy address
549 * @regnum: register number to read
551 * Read a MDIO bus register. Caller must hold the mdio bus lock.
553 * NOTE: MUST NOT be called from interrupt context.
555 int __mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)
559 WARN_ON_ONCE(!mutex_is_locked(&bus->mdio_lock));
561 retval = bus->read(bus, addr, regnum);
563 trace_mdio_access(bus, 1, addr, regnum, retval, retval);
567 EXPORT_SYMBOL(__mdiobus_read);
570 * __mdiobus_write - Unlocked version of the mdiobus_write function
571 * @bus: the mii_bus struct
572 * @addr: the phy address
573 * @regnum: register number to write
574 * @val: value to write to @regnum
576 * Write a MDIO bus register. Caller must hold the mdio bus lock.
578 * NOTE: MUST NOT be called from interrupt context.
580 int __mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)
584 WARN_ON_ONCE(!mutex_is_locked(&bus->mdio_lock));
586 err = bus->write(bus, addr, regnum, val);
588 trace_mdio_access(bus, 0, addr, regnum, val, err);
592 EXPORT_SYMBOL(__mdiobus_write);
595 * mdiobus_read_nested - Nested version of the mdiobus_read function
596 * @bus: the mii_bus struct
597 * @addr: the phy address
598 * @regnum: register number to read
600 * In case of nested MDIO bus access avoid lockdep false positives by
601 * using mutex_lock_nested().
603 * NOTE: MUST NOT be called from interrupt context,
604 * because the bus read/write functions may wait for an interrupt
605 * to conclude the operation.
607 int mdiobus_read_nested(struct mii_bus *bus, int addr, u32 regnum)
611 BUG_ON(in_interrupt());
613 mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
614 retval = __mdiobus_read(bus, addr, regnum);
615 mutex_unlock(&bus->mdio_lock);
619 EXPORT_SYMBOL(mdiobus_read_nested);
622 * mdiobus_read - Convenience function for reading a given MII mgmt register
623 * @bus: the mii_bus struct
624 * @addr: the phy address
625 * @regnum: register number to read
627 * NOTE: MUST NOT be called from interrupt context,
628 * because the bus read/write functions may wait for an interrupt
629 * to conclude the operation.
631 int mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)
635 BUG_ON(in_interrupt());
637 mutex_lock(&bus->mdio_lock);
638 retval = __mdiobus_read(bus, addr, regnum);
639 mutex_unlock(&bus->mdio_lock);
643 EXPORT_SYMBOL(mdiobus_read);
646 * mdiobus_write_nested - Nested version of the mdiobus_write function
647 * @bus: the mii_bus struct
648 * @addr: the phy address
649 * @regnum: register number to write
650 * @val: value to write to @regnum
652 * In case of nested MDIO bus access avoid lockdep false positives by
653 * using mutex_lock_nested().
655 * NOTE: MUST NOT be called from interrupt context,
656 * because the bus read/write functions may wait for an interrupt
657 * to conclude the operation.
659 int mdiobus_write_nested(struct mii_bus *bus, int addr, u32 regnum, u16 val)
663 BUG_ON(in_interrupt());
665 mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
666 err = __mdiobus_write(bus, addr, regnum, val);
667 mutex_unlock(&bus->mdio_lock);
671 EXPORT_SYMBOL(mdiobus_write_nested);
674 * mdiobus_write - Convenience function for writing a given MII mgmt register
675 * @bus: the mii_bus struct
676 * @addr: the phy address
677 * @regnum: register number to write
678 * @val: value to write to @regnum
680 * NOTE: MUST NOT be called from interrupt context,
681 * because the bus read/write functions may wait for an interrupt
682 * to conclude the operation.
684 int mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)
688 BUG_ON(in_interrupt());
690 mutex_lock(&bus->mdio_lock);
691 err = __mdiobus_write(bus, addr, regnum, val);
692 mutex_unlock(&bus->mdio_lock);
696 EXPORT_SYMBOL(mdiobus_write);
699 * mdio_bus_match - determine if given MDIO driver supports the given
701 * @dev: target MDIO device
702 * @drv: given MDIO driver
704 * Description: Given a MDIO device, and a MDIO driver, return 1 if
705 * the driver supports the device. Otherwise, return 0. This may
706 * require calling the devices own match function, since different classes
707 * of MDIO devices have different match criteria.
709 static int mdio_bus_match(struct device *dev, struct device_driver *drv)
711 struct mdio_device *mdio = to_mdio_device(dev);
713 if (of_driver_match_device(dev, drv))
717 return mdio->bus_match(dev, drv);
722 static int mdio_uevent(struct device *dev, struct kobj_uevent_env *env)
726 /* Some devices have extra OF data and an OF-style MODALIAS */
727 rc = of_device_uevent_modalias(dev, env);
734 struct bus_type mdio_bus_type = {
736 .match = mdio_bus_match,
737 .uevent = mdio_uevent,
739 EXPORT_SYMBOL(mdio_bus_type);
741 int __init mdio_bus_init(void)
745 ret = class_register(&mdio_bus_class);
747 ret = bus_register(&mdio_bus_type);
749 class_unregister(&mdio_bus_class);
755 #if IS_ENABLED(CONFIG_PHYLIB)
756 void mdio_bus_exit(void)
758 class_unregister(&mdio_bus_class);
759 bus_unregister(&mdio_bus_type);
761 EXPORT_SYMBOL_GPL(mdio_bus_exit);
763 module_init(mdio_bus_init);
764 /* no module_exit, intentional */
765 MODULE_LICENSE("GPL");
766 MODULE_DESCRIPTION("MDIO bus/device layer");